Out this weekend, Doctor Strange introduces Benedict Cumberbatch as Doctor Stephen Strange, the Sorcerer Supreme of the Marvel Universe. Here’s a few things you need to know about Doctor Strange’s comic-book origins and what to expect when you watch Marvel’s latest film.

DOCTOR STRANGE

In the comic, Strange is a renowned surgeon who cares only about his career and fame, until his life is thrown for a loop when he gets into a car accident and damages his hands. Seeking treatment, he travels to the Himalayas to find the Ancient One. He ultimately becomes the Ancient One’s apprentice and learns to master the mystical arts. Strange’s origin story is similar in the film, except he is led to the Himalayas not by overhearing two sailors (how ’60s) but by a man who learned how to walk again after a spinal injury. He’s reticent to learn the mystical arts and protect the world; he only wants to heal his hands to return to his career. But once he sees the good he can do, he accepts his role in protecting the Earth.

THE ANCIENT ONE

In the comics, Doctor Strange started as a racist Asian caricature before transforming into the white male lead of his own stories. Similarly, the Ancient One was a man, drawn as a Fu Manchu type who lived in Kamar-Taj, somewhere in the Himalayan mountains.

The movie, however, removes most references to Asian culture and goes for a bit of a generic mysticism led by the Ancient One, played by Tilda Swinton, who is now Celtic rather than Asian. Making the Ancient One a Celtic woman rather than an Asian stereotype might have seemed like a good idea, but it still earned the film accusations of whitewashing.

MORDO

Doctor Strange initially wins the trust of the Ancient One when he saves him from the villainous Baron Mordo. In the film, Chiwetel Ejiofor portrays Mordo as friend and mentor to Strange as he studies under the Ancient One. He operates more like the Falcon (Anthony Mackie) to Cumberbatch’s Captain America (Chris Evans), rather than being the supervillain he is in the comics.

WONG

In the comics, Wong serves as Strange’s valet. In 2016, having Wong in a subservient role wouldn’t exactly fly. Wong is the protector of the library at Kamar-Taj in the film and has no time for Strange’s arrogance. He even gets into the mix in the final battle as a sorcerer in his own right.

KAECILIUS

The original version of Kaecilius is as one of Baron Mordo’s disciples who assisted him in attempting to kill the Ancient One. In the film Doctor Strange, Kaecilius takes on the role Mordo had in the comics. He’s a former disciple of the Ancient One who becomes disillusioned with her and attempts to bring the Dark Dimension being Dormammu to Earth.

CHRISTINE PALMER

Christine Palmer’s inclusion in Doctor Strange might be the most surprising to comic-book fans, because she’s actually from the pages of Night Nurse. “Night Nurse” has been the moniker of three women in Marvel Comics, all of whom have specialized in helping injured superheroes. Currently, Claire Temple has the de facto role of the Night Nurse in the Marvel Netflix shows (she was even snarkily referred to as “night nurse” by one of Cottonmouth’s lackeys in Luke Cage). Christine Palmer is the name of one of the women who became Night Nurse in the comics, but she doesn’t seem to have that role in the Marvel Cinematic Universe so far — she’s Strange’s ex-girlfriend who helps him when he’s in danger.

Strange’s actual girlfriend from the comics, a sorceress by the name of Clea, makes no appearance in the film.

DORMAMMU

Dormammu, the Big Bad of Doctor Strange, is a being from the Dark Dimension who tries to take over Earth every so often, battling with Doctor Strange and other superheroes. In the film, Kaecilius attempts to bring him from the Dark Dimension so he can conquer Earth. But Dormammu looks less like his flaming-head comic-book counterpart in the film. He operates more like a Galactus from The Fantastic Four and has no corporeal body, except for a floating head in the space-like Dark Dimension.